Pipe lathes, also commonly referred to as split frame machines or clam shells, are generally well known, for example, in the power and petroleum industries.
An example of a pipe lathe 2 is shown in FIGS. 1 and 2. As shown in FIG. 2, the pipe lathe 2 is typically attached to a work piece 4 (e.g., without limitation, a pipe (shown in phantom line drawing in FIG. 2); a valve; a flange)), which has a round or circular perimeter and which needs to be cut, beveled, faced, bored or otherwise machined, for example, as part of a repair, new construction or maintenance service. The pipe lathe 2 typically includes two or more sections 6 and 8, which are segmented (e.g., split into two or more pieces) and designed to be coupled (e.g., bolted or otherwise suitably fastened) together to form a complete assembly 2 around the work piece 4 to be machined. Specifically, the first section is a stationary ring portion, or base 6, which clamps to the work piece 4 using feet or pads (generally indicated by reference numeral 10). The second section is a rotating portion 8 having a main gear ring 12 and being structured to be movably coupled to the base 6. The main gear ring 12 is a manufactured component that includes gear teeth 14, bearing interface grooves 16 (partially shown in hidden line drawing in FIG. 1), and tool mounting features 18 all incorporated into a single relatively thick and complex monolithic assembly, which makes up the rotating portion 8 of the pipe lathe 2. In the example of FIG. 2, a cutting tool 20 is shown in simplified form in phantom line drawing mounted on one of the tool mounting features 18.
In operation, the assembled pipe lathe 2 can be driven by a pneumatic, hydraulic or electric motor 22 (shown in simplified form in FIG. 1) or other suitable drive mechanism (not shown), that drives a number of gears 24 (one gear 24 is partially shown in hidden line drawing in FIG. 1) which, in turn, interface with the teeth 14 (FIG. 1) of the main gear ring 12 to turn the main gear ring 12 with respect to the base 6. Bearing assemblies 26 (FIG. 1) are coupled to the base 6 and cooperate with the aforementioned bearing interface grooves 16 of the main gear ring 12, thereby movably coupling the rotating portion 8 to the base 6. As the rotating portion 8 is driven by the motor 22 it rotates about the perimeter of the work piece 4, as indicated generally by arrow 28 of FIG. 2. As it does so, the desired tool (see, for example, cutting tool 20 shown in simplified form in phantom line drawing in FIG. 2) performs the desired machining operation (e.g., without limitation, cutting operation) on the work piece 4. It will be appreciated that, while the pipe lathe 2 is shown in FIG. 2 as being mounted on the exterior perimeter of the work piece 4, that it is also known to employ such a pipe lathe 2 on the interior circumference or perimeter of the work piece 4.
There is a need for improvement in pipe lathes, and in subassemblies therefore.